Acute aflatoxicosis in swines in Northeastern Brazil / Aflatoxicose aguda em suínos no Nordeste do Brasil

Background: Aflatoxins are hepatotoxic mycotoxins derived from the secondary metabolism of toxigenic fungi belonging to the genus Aspergillus, especially A. flavus and A. parasiticus. Aflatoxin B1 is the most important metabolite, because of its deleterious effect mainly to the liver, especially for its carcinogenic, mutagenic and haemorrhagic properties, and usually is detected in higher concentrations in contaminated substrates. This paper reports the epidemiological, clinical, pathological and toxicological aspects of an outbreak of acute aflatoxicosis in pigs raised in Northeastern Brazil. Case: The cases occurred in a complete cycle farm, in the city of Mossoró, Rio Grande do Norte, Northeastern Brazil, in pigs ingesting low quality (moldy) corn being produced and processed on the farm. Sixty (73.1%) out of 82 two to five-months old pigs were clinicaly affected and 54 (65.8%) died. All animals showed fever, weight loss, tachycardia, tachypnea, lethargy, muscle tremors, muscle weakness and diarrhea. The clinical course ranged from five to 48 hours. Adult pigs were not affected. At necropsies, generalized jaundice, ascites, hydropericardium, petechial hemorrhages in the mesentery, subcutaneous edema and mesocolon were observed. The liver was yellow-orange with reddish diffuse multifocal areas, enlarged and extremely friable. Histologically there was swelling of hepatocytes [...]

Acute aflatoxicosis in swines in Northeastern Brazil / Aflatoxicose aguda em suínos no Nordeste do Brasil

Background: Aflatoxins are hepatotoxic mycotoxins derived from the secondary metabolism of toxigenic fungi belonging to the genus Aspergillus, especially A. flavus and A. parasiticus. Aflatoxin B1 is the most important metabolite, because of its deleterious effect mainly to the liver, especially for its carcinogenic, mutagenic and haemorrhagic properties, and usually is detected in higher concentrations in contaminated substrates. This paper reports the epidemiological, clinical, pathological and toxicological aspects of an outbreak of acute aflatoxicosis in pigs raised in Northeastern Brazil. Case: The cases occurred in a complete cycle farm, in the city of Mossoró, Rio Grande do Norte, Northeastern Brazil, in pigs ingesting low quality (moldy) corn being produced and processed on the farm. Sixty (73.1%) out of 82 two to five-months old pigs were clinicaly affected and 54 (65.8%) died. All animals showed fever, weight loss, tachycardia, tachypnea, lethargy, muscle tremors, muscle weakness and diarrhea. The clinical course ranged from five to 48 hours. Adult pigs were not affected. At necropsies, generalized jaundice, ascites, hydropericardium, petechial hemorrhages in the mesentery, subcutaneous edema and mesocolon were observed. The liver was yellow-orange with reddish diffuse multifocal areas, enlarged and extremely friable. Histologically there was swelling of hepatocytes [...](AU)

Avaliação de uma estirpe não toxigênica para prevenção de diarreia neonatal em leitões por clostridioides ( clostridium ) difficile

Clostridioides (Clostridium) difficile é um dos maiores causadores de diarreia neonatal em suínos e estudos tem apontado para um possível potencial zoonótico deste microrganismo. Apesar da importância do patógeno, não existem medidas específicas para a prevenção e controle da infecção por C. difficile (ICD). Desta forma, o objetivo do presente estudo foi caracterizar genotipicamente e avaliar o potencial de proteção de uma estirpe não toxigênica de C. difficile (NTCD), nomeada de Z31, contra a ICD em suínos. Para tal, o estudo foi dividido em cinco etapas: (1) Caracterização genotípica da estirpe Z31; (2) Avaliação da capacidade preventiva da estirpe Z31 contra a ICD em modelo experimental suíno; (3) Avaliação da capacidade preventiva da estirpe Z31 contra a ICD em uma granja comercial; (4) Avaliação de cinco meios de cultura para a produção e esporulação da estirpe Z31; e (5) Avaliação da viabilidade temporal de esporos liofilizados da estirpe Z31. O sequenciamento genômico revelou que a estirpe Z31 possui um cromossomo circular de 4.298.263 pares de base (bp), contendo genes responsáveis por produção e estabilidade dos esporos (spo0A), aderência intestinal (slpA) e formação de biofilme (fliD), porém, ausência dos genes codificadores das toxinas. Em modelo experimental em suínos neonatos, a Z31 preveniu a ICD, reduzindo os sinais clínicos, as lesões macro e microscópicas e a eliminação fecal do agente. Em uma granja comercial, mesmo na presença de outros enteropatógenos, a Z31 reduziu a ocorrência de ICD, a eliminação fecal de C. difficile toxigênico e a ocorrência de diarreia neonatal suína. Os meios BHI e RCM proporcionaram as maiores taxas de crescimento in vitro da estirpe Z31, atingindo concentrações de 6,57 × 106 UFC/mL com proporção de esporos superiores a 98%. Quando liofilizada, a estirpe Z31 manteve uma viabilidade aceitável tanto em temperatura ambiente quanto resfriada, de forma que 40-50% da carga total ainda se encontrava viável após 2 anos de armazenamento. Como conclusão, a estirpe Z31 foi capaz de prevenir a ICD em suínos e demonstrou características desejáveis para o seu potencial uso comercial.

Clostridioides (Clostridium) difficile is one of the main causes of porcine neonatal diarrhea and studies has shown the possible zoonotic potential of this microorganism. Despite the importance of this pathogen, there are no specific measures for the prevention and control of C. difficile infection (CDI). Thus, the aim of the present study was to characterize genotypically and evaluate the protective potential of a non-toxigenic C. difficile strain (NTCD), named Z31, against CDI in piglets. For this purpose, the study was divided into five stages: (1) Genotypic characterization of the strain Z31; (2) Evaluation of the preventive capacity of the strain Z31 against the CDI in experimental pig model; (3) Evaluation of the preventive capacity of the strain Z31 against CDI in a commercial farm; (4) Evaluation of five culture media for the production and sporulation of the strain Z31; and (5) Evaluation of the temporal viability of freeze-dried spores of the strain Z31. Genomic sequencing revealed that the strain Z31 has a circular chromosome of 4,298,263 base pairs (bp) containing genes responsible for spore production and stability (spo0A), intestinal adhesion (slpA) and biofilm formation (fliD), but absence of toxins encoding genes. In an experimental model in neonatal pigs, the strain Z31 prevented CDI, reducing clinical signs, macro and microscopic lesions and fecal elimination of the agent. In a commercial farm, even in the presence of other enteropathogens, the Z31 reduced the occurrence of CDI, the fecal elimination of toxigenic C. difficile and the occurrence of neonatal porcine diarrhea. The BHI and RCM media provided the highest in vitro growth rates of the strain Z31, reaching concentrations of 6.57 × 106 CFU/ml with spore ratio greater than 98%. After lyophilization, the strain Z31 maintained acceptable viability at both, ambient and cooled temperatures, so that 40-50% of the total charge was still viable after 2 years of storage. In conclusion, the strain Z31 was able to prevent CDI in pigs and demonstrated desirable characteristics for its potential commercial use.

Pathogenesis of Senecavirus A: integration of the blood brain barrier in newborn piglets with the epidemic transient neonatal losses syndrome.

Senecavirus A (SVA), família Picornaviridae, é o agente etiológico de uma doença vesicular clinicamente indistinguível das outras doenças vesiculares dos suínos, destacando-se a febre aftosa, doença animal de maior importância epidemiológica mundial. O SVA é o agente etiológico de duas síndromes, acometendo suínos de diferentes idades: Doença Vesicular Idiopática Suína (PIVD) e Perdas Neonatais Epidêmicas Transientes (ETNL). O objetivo desse estudo foi descrever os achados macroscópicos, histopatológicos, imuno-histoquímicos (IHQ) e ultra-estruturais associados a infecção natural por SVA e determinar o possível tropismo do vírus em diferentes tecidos de leitões neonatos do Sul e Suldeste do Brasil. Foram realizadas autopsias de 54 leitões com sinais clínicos associados a ETNL. Destes, (80%; 43/54) leitões foram positivos na IHQ e confirmados na transcrição reversa seguida de reação em cadeia da polimerase (RT-PCR) para SVA. A maioria (81%; 35/43) dos leitões que morreram por ETNL tinham entre 2-6 dias de idade. As lesões macroscópicas mais frequentes durante as autopsias foram fezes líquidas (91%; 39/43), hemorragias petequiais renais (79%; 34/43), pneumonia intersticial (77%; 33/43), lesão ulcerativa na banda coronária (35%; 15/43), edema de mesocólon (32%; 14/43), vesículas no focinho (30%; 13/43) e linfadenopatia (28%; 12/43). Na histopatologia foi observado degeneração balonosa do urotélio da bexiga (100%; 43/43), pelve urinária (95%; 41/43), enterite atrófica (93%; 40/43), meningoencefalite não supurativa e plexo coroidite (7%; 3/43). A imunomarcação positiva ao SVA foi observada no endotélio e células epiteliais do plexo coroide (CP) e nos tecidos epiteliais de todos os órgãos avaliados, exceto, nos tecidos pulmonar e linfoide. A microscopia eletrônica de transmissão revelou degeneração hidrópica dos enterócitos apicais do intestino delgado, degeneração hidrópica, apoptose e necrose do endotélio dos capilares fenestrados e ependimócitos do CP associados a partículas virais intralesionais compatível com SVA. Este estudo demonstrou que o SVA é um vírus epiteliotrópico, apresentando imunomarcação positiva para o epitélio de transição da pelve renal, ureter e vesícula urinária, endotélio dos capilares do CP cerebral, no epitélio da língua e nos enterócitos apicais do intestino delgado. Esses resultados demonstram que a degeneração balonosa observada em diferentes tecidos/órgãos foram causadas pelo SVA e sugerem que os sinais neurológicos observados em alguns leitões foram decorrentes da meningoencefalite não supurativa induzida pelo SVA. Além disso, os resultados iniciais sugerem que o SVA pode atuar como um enterovírus, produzindo uma doença entérica inicial com posterior disseminação neurológica.

Senecavirus A (SVA), Picornaviridae family, is the aetiological agent of a vesicular disease that is clinically indistinguishable from the other known vesicular diseases of the pigs, highlighting the foot-and-mouth disease, an animal disease of foremost epidemiological importance worldwide. SVA is the aetiological agent of two syndromes affecting different age groups of swine: Porcine Idiopathic Vesicular Disease (PIVD) and Epidemic Transient Neonatal Losses (ETNL). The objective of this study were to describe the gross, histopathological, immunohistochemical (IHC) and ultrastructural findings associated with natural infection by SVA, and to determine the possible tropism of the virus for different tissues of newborn piglets from Brazil. Autopsies of 54 piglets with clinical signs associated with ETNL were done. Of these, 80% (43/54) piglets contained the antigens of SVA IHC and SVA RNA was identified by Reverse Transcription-Polymerase Chain Reaction (RT-PCR) for SVA. Most (81%; 35/43) of the piglets that died of ETNL were between 2-6 days of age. The most frequent macroscopic lesions during autopsy were liquid faeces (91%; 39/43), renal petechial haemorrhages (79%; 34/43), interstitial pneumonia (77%; 33/43), ulcerative lesions at the coronary band (35%; 15/43), oedema of the mesocolon (32%; 14/43), vesicles at the snout (30%; 13/43) and lymphadenopathy (28%; 12/43). Histopathology revealed ballooning degeneration of the urothelium of the bladder (100%; 43/43), urinary pelvis (95%, 41/43), atrophic enteritis (93%, 40/43), and nonsuppurative meningoencephalitis and plexus choroiditis (7%; 3/43). Positive immunostaining for SVA was observed at the endothelium and epithelial of the choroid plexus (CP) of the brain and in epithelial tissues of all organs evaluated, except in the lungs and lymphoid tissues. Transmission electron microscopy demonstrated hydropic degeneration of superficial enterocytes of the small intestine, hydropic degeneration, apoptosis, and endothelial necrosis of fenestrated capillaries and ependymocytes of the CP associated with intralesional viral particles consistent with SVA. This study has demonstrated that SVA is an epitheliotropic virus, has positive immunoreactivity for the transitional epithelium of the renal pelvis, ureter, urinary bladder, and with endothelial identification of viral antigens in the capillaries of the cerebral CP, tongue epithelium, and the superficial enterocytes of the small intestine. These results demonstrated that the ballooning degeneration observed in different tissue/organs were caused by SVA and suggest that the neurological signs observed in some piglets were due to SVA-induced nonsuppurative meningoencephalitis. In addition, initial results suggest that SVA may act as an enterovirus, producing an initial enteric disease with subsequent neurological dissemination.

A surveillance of enteropathogens in piglets from birth to seven days of age in Brazil / Levantamento dos enteropatógenos de leitões do nascimento a sete dias de idade no Brasil

The purpose of the study was to evaluate the real importance of anaerobic enteropathogens and rotavirus in contrast to more common agents as cause of diarrhea in piglets within the first week of life. Sixty 1- to 7-day-old piglets, 30 diarrheic and 30 non-diarrheic (control), from 15 different herds were selected, euthanized and necropsied. Samples of the jejunum, ileum, colon, cecum and feces were collected from the piglets and analyzed to determine the presence of the following enteropathogens: enterotoxigenic Escherichia coli (ETEC), Clostridium perfringens types A and C, Clostridium difficile, rotavirus and Isospora suis. Among diarrheic piglets, 23.3% were positive for C. difficile, 70% for C. perfringens type A cpb2+, 14.3% for rotavirus and 10% for ETEC. Among non-diarrheic control piglets, 10% were positive for C. difficile, 76.7% for C. perfringens type A cpb2+, 0% for rotavirus, 3.3% for ETEC and 3.3% for I. suis. C. perfringens type C was not detected in any of the animals. Histological lesions characteristic of C. difficile, E. coli and rotavirus were observed. However, no C. perfringens type A suggestive lesions were detected. There was a positive correlation between mesocolon edema and the presence of C. difficile toxins. Although C. perfringens type A cpb2+ was the most frequently detected enteropathogen, there was no association between its presence and diarrhea or macro or microscopic changes. C. difficile and Rotavirus were the most relevant pathogens involved with neonatal diarrhea in this study, and histopathology associated with microbiological test proved to be the key to reach a final diagnosis.(AU)

O objetivo do presente estudo foi avaliar a real importância de enteropatógenos anaeróbios e rotavirus em comparação à outros agentes mais comuns como causa de diarreia em leitões até cinco dias de idade. Leitões com 0 a 7 dias de vida, 30 diarreicos e 30 não diarreicos (controles) de 15 granjas diferentes foram eutanasiados e necropsiados. Amostras de jejuno, íleo, colon e ceco foram coletadas e submetidas à detecção dos seguintes enteropatógenos: Escherichia coli enterotoxigênica (ETEC), Clostridium perfringens, Clostridium difficile, rotavirus e Isospora suis. Entre os animais diarréicos, 23.3% foram positivos para C. difficile, 70% para C. perfringens tipo A cpb2+, 14.3% para rotavirus e 10% para ETEC. Entre os leitões não-diarréicos, 10% foram positivos para C. difficile, 76.7% para C. perfringens tipo A cpb2+, 3.3% para ETEC e 3.3% for I. suis. C. perfringens tipo C não foi detectado em nenhum animal. Lesões histológicas características de C. difficile, E. coli e rotavirus foram observadas. Por outro lado, nenhuma lesão sugestiva de C. perfringens foi detectada. Foi possível observar uma correlação positiva entre edema de mesocolon e presença das toxinas A/B. Apesar de C. perfringens tipo A cpb2+ ter sido o patógeno mais encontrado, nenhuma associação com lesões foi encontrada. C. difficile e Rotavirus foram os agentes mais relevantes associados à diarreia neonatal, e ficou demonstrada a relevância de associação de histopatologia com testes de detecção microbiológica para se firmar um diagnóstico.(AU)

TREMOR CONGÊNITO EM LEITÕES RECÉM-NASCIDOS E A INFECÇÃO POR PESTIVÍRUS SUÍNO ATÍPICO

Pestivírus suíno atípico (APPV) tem sido associado ao tremor congênito (TC) tipo A-II em leitões neonatos. Apesar do número de estudos sobre o APPV ter aumentado, as alterações histopatológicas, bem como outros aspectos relativos à caracterização antigênica e molecular do vírus e aspectos epidemiológicos da infecção em leitões ainda são pouco descritos. O objetivo do primeiro estudo foi descrever os achados patológicos e moleculares associados à infecção simultânea de APPV e teschovírus suíno (PTV) em leitões com manifestações clínicas de TC provenientes de um rebanho do estado do Paraná com altas taxas de letalidade em animais recém-nascidos. Em 2017, foram relatados casos de TC em leitegadas com alta letalidade neonatal em um rebanho paranaense e três leitões da mesma leitegada que morreram espontaneamente foram enviados para diagnóstico. As principais alterações patológicas encontradas em todos os leitões foram desmielinização secundária e hipomielinização no cerebelo, tronco encefálico e medula espinhal confirmadas por histopatologia e coloração Luxol Fast Blue. Alterações histopatológicas adicionais incluíram necrose neuronal multifocal, neuronofagia e gliose encontrados no córtex cerebral e medula espinhal e enterite atrófica de todos os leitões e edema no mesocólon de um deles. RNA de APPV e de PTV foi detectado por nested-RT-PCR no sistema nervoso central (SNC) dos leitões afetados, sendo que PTV também foi detectado no intestino e nas fezes. As alterações patológicas e os resultados moleculares demonstram que os leitões avaliados apresentavam infecção por APPV e PTV, o que pode ter ocasionado a alta letalidade (100%) de leitões recém-nascidos identificada nesse caso. No segundo estudo foram descritas as características histopatológicas da infecção espontânea singular por APPV em quatro leitões com sinais clínicos de TC. Os quatro leitões de dois dias de idade com TC foram avaliados por histopatologia, imunohistoquímica (IHQ) e análise molecular. As principais alterações histopatológicas no encéfalo e medula espinhal incluíram necrose neuronal, gliose, neuronofagia, satelitose, desmielinização, degeneração walleriana e necrose de células de purkinje. Na IHQ, realizada com o objetivo de detectar a proliferação da proteína ácida fibrilar glial (GFAP) em áreas afetadas do encéfalo e medula espinhal, demonstrou que a proliferação de células GFAP positivas e fibras era predominante em leitões com TC infectados com APPV em relação a leitões assintomáticos não infectados da mesma idade. As reações de nested-RT-PCR identificaram RNA de APPV no cérebro, cerebelo e tronco cerebral de todos os leitões, enquanto outros vírus (teschovírus suíno, sapelovírus suíno e vírus Seneca Valley) conhecidos por induzir sinais clínicos semelhantes não foram identificados. Estes resultados sugerem que as alterações histopatológicas induzidas pela infecção singular por APPV nos leitões avaliados são predominantemente degenerativas e necróticas e correlacionadas com as alterações identificadas no primeiro estudo. Com estes resultados podemos sugerir que a necrose neuronal, a gliose, a neuronofagia e a satelitose possam ser consideradas características histológicas importantes da infecção induzida por APPV em leitões recém-nascidos com sinais clínicos de TC.

Atypical porcine pestivirus (APPV) has been associated with congenital tremor (CT) type A-II in neonatal piglets. Although the number of APP-based studies is increasing, the histopathological alterations and other aspects related to the antigenic and molecular characterization of the virus and epidemiological aspects of the infection in piglets are still underreported. The objective of the first study was to describe the pathological and molecular findings associated with simultaneous infection of APPV and porcine teschovirus (PTV) in piglets with clinical manifestations of CT from a herd of Paraná State with high rates of lethality in newborn piglets. In 2017, CT cases were reported in litters with high neonatal mortality in a pig herd from Paraná and three piglets from the same litter that died spontaneously were sent for diagnosis. The main pathological alterations in all piglets were secondary demyelination and hypomyelination at the cerebellum, brainstem and spinal cord confirmed by histopathology and luxol fast bluecresyl violet stain. Additional histopathological alterations included multifocal neuronal necrosis, neuronophagia and gliosis found in the cerebral cortex and spinal cord of all piglets, and atrophic enteritis in all piglets and mesocolonic oedema in one piglet. APPV and PTV RNA was detected by nested-RT-PCR in the central nervous system of affected piglets, and PTV was also detected in the intestine and faeces. The pathological alterations and molecular results together suggested that the piglets evaluated had a dual infection by APPV and PTV, which probably was the cause of the high lethality (100%) of newborn piglets identified in this case. In the second study the histopathologic features of singular spontaneous APPV infection in four piglets with clinical signs of CT were described. Four two-day-old piglets with CT were evaluated by histopathology, immunohistochemistry (IHC), and molecular assay. The main histopathologic alterations at the brain and spinal cord included neuronal necrosis, gliosis, neuronophagia, satellitosis, demyelination, Wallerian degeneration, and Purkinje cell necrosis. In the IHC assay, performed to detect the proliferation of glial fibrillary acidic protein (GFAP) in affected areas of the brain and spinal cord revealed that the proliferation of GFAP+ cells and fibers was predominant in APPV-infected piglets relative to asymptomatic piglets of the same age group. The nested-RT-PCR assays identified APPV RNA in the cerebrum, cerebellum, and brainstem of all piglets, while other viruses (PTV, PSV, SVV) known to induce similar clinical signs were not identified. These results suggested that the histopathological alterations induced by singular APPV infection are predominantly degenerative and necrotic and correlate with alterations identified in the first study. With these results we can suggest that neuronal necrosis, gliosis, neuronophagia, and satellitosis should be considered as important histologic features of APPV-induced infection in newborn piglets with clinical signs of CT.

Surto de aflatoxicose em bezerros no Rio Grande do Sul / Outbreak of aflatoxicosis in calves in southern Brazil

Um surto de aflatoxicose crônica é relatado em bezerros de raça leiteira. Quarenta bezerros holandeses machos de quatro meses de idade e aproximadamente 100kg eram mantidos em gaiolas individuais de 1,5 x 1,5m e alimentados com uma ração constituída por feno de alfafa, milho quebrado e substituto de leite. Seis bezerros (15 por cento) morreram após apresentar uma doença caracterizada por mau desenvolvimento geral, diarreia, pelagem áspera, dor abdominal, tenesmo, prolapso de reto e bruxismo. Alguns bezerros "deitavam e rolavam" no chão da gaiola. A duração do curso clínico, segundo observado pelos proprietários, foi de 2-3 dias; muitos terneiros desse lote que não morreram permaneceram pouco desenvolvidos. Três bezerros foram necropsiados. Os achados de necropsia incluíam fígado firme e castanho-claro, marcados hidrotórax e ascite, e edema do mesentério, mesocólon e das dobras da mucosa do abomaso. Os principais achados histopatológicos estavam restritos ao fígado e consistiam de fibrose, moderada megalocitose, hiperplasia de ductos biliares e lesão veno-oclusiva. A procura por contaminação de Senecio spp. no feno de alfafa resultou negativa. A análise do milho do alimento dos bezerros por cromatografia de camada delgada revelou 5.136ppb de aflatoxina B1. O diagnóstico de aflatoxicose foi feito baseado nos sinais clínicos e patologia característicos, na ausência de Senecio spp. na alimentação dos terneiros e na presença de altos níveis de aflatoxina no milho da alimentação dos bezerros.(AU)

An outbreak of chronic aflatoxicosis is reported in dairy calves. Forty 4-month-old male Holstein calves of approximately 100kg were kept in individual cages of 1.5 x 1.5m and were fed a ration constituted by alfalfa hay, broken corn and milk substitute. Six calves (15 percent) died after presenting a disease characterized by general unthriftiness, diarrhea, rough hair coats, abdominal pain, prolapsed rectum, grinding of teeth, and lying down and rolling. The clinical course, as observed by the owners, was 2-3 days; however many calves in this lot that did not die, remained underdeveloped. Three calves were necropsied. Necropsy findings included firm, light tan livers and marked hydrothorax, ascites and edema of the mesentery, mesocolon and of the mucosal folds of the abomasum. Main histopathological changes were restricted to the liver and consisted of fibrosis, moderate megalocytosis, biliary duct hyperplasia and veno-occlusive disease. The search for Senecio spp. contamination in the alfalfa hay resulted negative. The analysis by thin layer chromatography of the corn fed to calves revealed 5,136 ppb of aflatoxin B1. A diagnosis of aflatoxicosis was made based on the characteristic clinical signs and pathology, on the absence of Senecio spp. in the food and on the presence of high levels of aflatoxin in the corn fed to the calves.(AU)

Neonatal piglets mesocolon edema and colitis due to Clostridium difficile infection: prevalence, clinical disease and pathological studies

Clostridium difficile is a Gram-positive opportunistic anaerobic bacterium found in the soil, water as well as the digestive tract of several species of mammals. Currently in high-health herds and not related with antibiotic treatment, C. difficile has been emerged in association with neonatal catarrhal, fibrinous or purulent colitis in 2 to 7 day-old piglets. Mesocolon edema and colitis with a "volcano" lesion e pathological key marks of C. difficile infection. In farm 1, the prevalence of neonatal piglet mesocolon edema and colitis was evaluated in an extensive study of postmortem preweaning mortality. Lectinhistochemistry pattern of normal colon and colon with edema and colitis were analyzed in order to provide more accurate information related with pathogenesis of C.difficile infection. In farm 2, a clinical description of an outbreak of neonatal colitis in piglets due to C. difficile infection was reported. A total 820 piglets were post-mortem examined, from them, 8 cases were classified as suspected of C. difficile infection (0.1%). Age of affected piglets varied between 3 to 14 days. In all of them, the key mark was the severe mesocolon edema and 2 cases were characterized by focal necrosis and loss of epithelial cells associated with a focal infiltration of neutrophils and macrophages in the lamina propria and lumen like erupted volcano. Lectins SBA and DBA that has affinity to a Gal epitope were negative in normal samples but reacted strongly positive at the glycocalix of the villi enterocytes of the affected samples indicating a change in the carbohydrates pattern of the cells surfaces that might favor the binding of C. difficile toxin A (TcdA). In farm 2, from 11 examined piglets, 6 of them (54%) showed different degree of mesocolon edema and in only 2 of them; volcano lesions were the main histopathological findings. Rectal swab from 8 diarrheic and 5 postmortem examined piglets were surveyed for eltA estl estll and stx2, virulence gens of E. coli and all samples were negative. Clostridium difficile toxins A and B were identified only in the sample with severe gross and microscopic changes. Isolation of difficile was unsuccessfully. Infection of C. difficile is present in Argentinean pig farms. Diagnosis of subclinical infection might be negligent if post-mortem studies of preweaning mortality at weekly intervals are not performed. However, when clinical disease appeared, mortality might be high as it was reported in the farm 2. Comparative lectinhistochemistry studies from field cases added further information of the carbohydrates present on glycocalix of villi enterocytes related with toxin receptors.

Co-infection by porcine circovirus type 2 and porcine parvovirus in aborted fetuses and stillborn piglets in southern Brazil / Co-infecção por circovírus suíno tipo 2 e parvo-vírus suíno em fetos abortados e natimortos suínos no Sul do Brasil

Porcine circovirus types 1 and 2 (PCV1, PCV2) and porcine parvovirus (PPV) are widespread in pig populations around the world. Nevertheless, only PCV2 has been associated with different clinical syndromes, thus representing a major problem to the pig industry. The association of cases of swine abortions and stillborns with PCV1 and PCV2 and PPV was studied retrospectively (2005-2007). Additional pathogens were also investigated in lesioned fetuses. The studied litters included stillborn piglets and several mummified fetuses of varied sizes. Ventricular dilatation, myocardial pale areas, and mesocolic edema were the gross lesions. Escherichia coli was detected as co-infecting with PCV2 the cases in which mesocolic edema was seen. Microscopic lesions included non-suppurative myocarditis, myocardial necrosis and fibrosis, mineralization foci and intranuclear inclusion bodies in cardiomyocytes, and interstitial mononuclear pneumonia. Samples from 7 (5.78 per cent) of 121 aborted fetuses and stillborn piglets had lesions consistent with a viral cause and showed both positive anti-PCV2 immunostaining as well as PCV2-PCR. In samples from 3 (2.47 per cent) of these 7 fetuses, co-infection with PPV was confirmed by Nested-PCR. Both viruses were detected in fetuses at different stages of gestation. Viral antigens of PCV2 were detected by immunohistochemistry mainly in macrophages and myocytes. PCV1 individually was not detected in any of these affected fetuses, but it was associated with PCV2 and/or PPV in some of them. These findings indicate that PCV2 alone or in association with PPV should be kept in mind when investigating causes of infectious abortion in pigs in Brazil.(AU)

Estudou-se retrospectivamente (2005-2007) a associação de casos de abortos e natimortos suínos com infecções por circovírus suíno (PCV) tipos 1 e 2 e parvovírus suíno (PPV). Outros agentes patogênicos foram pesquisados em amostras de fetos com lesões. O estudo incluiu natimortos e fetos mumificados de tamanhos variados. Dilatação ventricular, áreas pálidas miocárdicas e edema de mesocólon foram as lesões macroscópicas observadas. Escherichia coli co-infectou com PCV2 as amostras dos casos com edema de mesocólon. Lesões microscópicas incluíram miocardite não supurativa, necrose e fibrose miocárdicas, focos de mineralização e corpúsculos de inclusão em cardiomiócitos e pneumonia intersticial mononuclear. Entre os 121 fetos suínos abortados ou natimortos analisados, sete (5,78 por cento) tinham lesões compatíveis com origem viral e foram positivos pelas técnicas de imunoistoquímica e PCR para PCV2. Além disso, três (2.47 por cento) desses sete casos também foram confirmados como co-infectados com PPV através da PCR. Antígenos de PCV2 foram observados principalmente em macrógafos e no interior de miócitos dos fetos suínos abortados e natimortos. PCV2 e PPV foram detectados em diferentes estágios de gestação. PCV1 não foi associado isoladamente com feto ou natimorto afetado, mas estava presente em associação com PCV2 e/ou PPV em alguns desses produtos. Esses achados indicam que a infecção por PCV2, isoladamente ou em associação com PPV, deve ser considerada no diagnóstico de aborto infeccioso suíno no Brasil.(AU)

Neonatal piglets mesocolon edema and colitis due to Clostridium difficile infection: prevalence, clinical disease and pathological studies

Clostridium difficile is a Gram-positive opportunistic anaerobic bacterium found in the soil, water as well as the digestive tract of several species of mammals. Currently in high-health herds and not related with antibiotic treatment, C. difficile has been emerged in association with neonatal catarrhal, fibrinouspurulent colitis in 2 to 7 day-old piglets. Mesocolon edema and colitis with a volcano lesion are pathological key marks of C. difficile infection.  In farm 1, the prevalence of neonatal piglet mesocolon edema and colitis was evaluated in an extensive study of postmortem preweaning mortality. Lectinhistochemistry pattern of normal colon and colon with edema and colitis were analyzed in order to provide more accurate information related with pathogenesis of C.difficile infection.  In farm 2, a clinical description of an outbreak of neonatal colitis in piglets due to C. difficile infection was reported. A total 820 piglets were post-mortem examined, from them, 8 cases were classified as suspected of C. difficile infection (0.1%). Age of affected piglets varied between 3 to 14 days. In all of them, the key mark was the severe mesocolon edema and 2 cases were characterized by focal necrosis and loss of epithelial cells associated with a focal infiltration of neutrophils and macrophages in the lamina propria and lumen like erupted volcano. Lectins SBA and DBA that has aff

Surto de diarréia por Clostridium difficile em leitões no Brasil / An outbreak of Clostridium difficile-associated diarrhea in piglets in Brazil

Apesar da crescente importância de Clostridium difficile como causador de diarréia em leitões, são escassos os estudos e relatos da doença no Brasil. O objetivo do presente trabalho é descrever um surto de diarréia por C. difficile em uma granja localizada no Rio Grande do Sul, Brasil. A frequência de diarréia em leitões com até 7 dias de vida aumentou de uma média de 2% para aproximadamente 20%. Leitões necropsiados apresentavam edema de mesocólon e, na avaliação histopatológica, uma colite neutrofílica necrotizante severa foi observada. O conteúdo intestinal foi positivo para as toxinas A e B e negativo para outros patógenos pesquisados. A associação dos sinais clínicos, achados post mortem e resultados dos exames laboratoriais permite confirmar o diagnóstico de diarréia por C. difficile. O presente relato confirma C. difficile como um patógeno de suínos no Brasil e destaca a necessidade de inclusão desse enteropatógeno no diagnóstico laboratorial para as diarréias em leitões.

In spite of the substantial role of Clostridium difficile in causing diarrhea in piglets, there have been few reports of the disease caused by this bacterium in Rio Grande do Sul, Brazil. In this paper, we describe an outbreak of C. difficile-associated diarrhea in a pig farm in Brazil. The diarrhea rate increased in piglets 1-to-7 days old from an average of 2% to approximately 20%. Necropsied piglets showed mesocolon edema, and in a histological evaluation, severe necrotizing neutrophilic colitis was observed. The intestinal contents were positive for the A/B toxins of C. difficile and negative for other tested enteropathogens. The association between the clinical signs, post mortem findings and laboratory exams confirmed the diagnosis of C. difficile-associated diarrhea. The present report confirms C. difficile as a pathogen in swine in Brazil and highlights the need for up to date routine laboratory protocols for the diagnosis of this disease in swine.

Surto de diarréia por Clostridium difficile em leitões no Brasil / An outbreak of Clostridium difficile-associated diarrhea in piglets in Brazil

Apesar da crescente importância de Clostridium difficile como causador de diarréia em leitões, são escassos os estudos e relatos da doença no Brasil. O objetivo do presente trabalho é descrever um surto de diarréia por C. difficile em uma granja localizada no Rio Grande do Sul, Brasil. A frequência de diarréia em leitões com até 7 dias de vida aumentou de uma média de 2% para aproximadamente 20%. Leitões necropsiados apresentavam edema de mesocólon e, na avaliação histopatológica, uma colite neutrofílica necrotizante severa foi observada. O conteúdo intestinal foi positivo para as toxinas A e B e negativo para outros patógenos pesquisados. A associação dos sinais clínicos, achados post mortem e resultados dos exames laboratoriais permite confirmar o diagnóstico de diarréia por C. difficile. O presente relato confirma C. difficile como um patógeno de suínos no Brasil e destaca a necessidade de inclusão desse enteropatógeno no diagnóstico laboratorial para as diarréias em leitões.

In spite of the substantial role of Clostridium difficile in causing diarrhea in piglets, there have been few reports of the disease caused by this bacterium in Rio Grande do Sul, Brazil. In this paper, we describe an outbreak of C. difficile-associated diarrhea in a pig farm in Brazil. The diarrhea rate increased in piglets 1-to-7 days old from an average of 2% to approximately 20%. Necropsied piglets showed mesocolon edema, and in a histological evaluation, severe necrotizing neutrophilic colitis was observed. The intestinal contents were positive for the A/B toxins of C. difficile and negative for other tested enteropathogens. The association between the clinical signs, post mortem findings and laboratory exams confirmed the diagnosis of C. difficile-associated diarrhea. The present report confirms C. difficile as a pathogen in swine in Brazil and highlights the need for up to date routine laboratory protocols for the diagnosis of this disease in swine.

Surto de diarréia por Clostridium difficile em leitões no Brasil / An outbreak of Clostridium difficile-associated diarrhea in piglets in Brazil

Apesar da crescente importância de Clostridium difficile como causador de diarréia em leitões, são escassos os estudos e relatos da doença no Brasil. O objetivo do presente trabalho é descrever um surto de diarréia por C. difficile em uma granja localizada no Rio Grande do Sul, Brasil. A frequência de diarréia em leitões com até 7 dias de vida aumentou de uma média de 2% para aproximadamente 20%. Leitões necropsiados apresentavam edema de mesocólon e, na avaliação histopatológica, uma colite neutrofílica necrotizante severa foi observada. O conteúdo intestinal foi positivo para as toxinas A e B e negativo para outros patógenos pesquisados. A associação dos sinais clínicos, achados post mortem e resultados dos exames laboratoriais permite confirmar o diagnóstico de diarréia por C. difficile. O presente relato confirma C. difficile como um patógeno de suínos no Brasil e destaca a necessidade de inclusão desse enteropatógeno no diagnóstico laboratorial para as diarréias em leitões.

In spite of the substantial role of Clostridium difficile in causing diarrhea in piglets, there have been few reports of the disease caused by this bacterium in Rio Grande do Sul, Brazil. In this paper, we describe an outbreak of C. difficile-associated diarrhea in a pig farm in Brazil. The diarrhea rate increased in piglets 1-to-7 days old from an average of 2% to approximately 20%. Necropsied piglets showed mesocolon edema, and in a histological evaluation, severe necrotizing neutrophilic colitis was observed. The intestinal contents were positive for the A/B toxins of C. difficile and negative for other tested enteropathogens. The association between the clinical signs, post mortem findings and laboratory exams confirmed the diagnosis of C. difficile-associated diarrhea. The present report confirms C. difficile as a pathogen in swine in Brazil and highlights the need for up to date routine laboratory protocols for the diagnosis of this disease in swine.